ABSTRACT
This chapter focuses on the special difficulties presented by the classical concept of causality in biology. The three aspects of causality, such as explanation, prediction and teleology, must be the cardinal points in any discussion of causality and were quite rightly singled out as such by E. Nagel. Biology can make a significant contribution to all three of them. As soon as one goes beyond the level of purely descriptive structural biology one finds two very different areas, which may be designated functional biology and evolutionary biology. Any biologist working in one of the fields must have a knowledge and appreciation of the other field if he wants to avoid the label of a narrow-minded specialist. The functional biologist is vitally concerned with the operation and interaction of structural elements, from molecules up to organs and whole individuals. The evolutionary biologist differs in his method and in the problems in which he is interested.
